Bulletin d’avalanche

Tetons

Bridger-Teton Avalanche Center
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Danger d’avalanche

Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 7 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Dangerous avalanche conditions exist at the mid and upper elevations. There, numerous large to very large persistent slab avalanches released naturally or were human triggered on Friday. Skiers and riders venturing into terrain that had an existing snowpack prior to Thanksgiving are likely to trigger similar slides. Involvement in one of these avalanches would likely have a fatal outcome. Recently developed wind slabs, with depths of one to two feet, could still be triggered by backcountry travelers in steep, wind-loaded terrain, and these smaller slides have the potential to step down and release a deeper persistent slab. Expert snowpack evaluation and conservative terrain choices will be essential for safe travel in avalanche terrain. At the lower elevations, skiers and riders might be able to trigger a small, isolated pocket of soft slab in very steep avalanche starting zones.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–3

    Weak, faceted snow persists near the base of the snowpack on slopes that held snow prior to Thanksgiving. Last week’s storm cycles added a substantial load to these weak basal layers, and backcountry travelers are likely to trigger these slabs with depths of three to five feet. While the likelihood of triggering these slabs is decreasing, the consequences remain the same. These avalanches could easily kill you or someone in your party. They are breaking high into lower angle terrain, running long distances and can also be remotely triggered. Remember, previous tracks are not an indication of stability with a persistent slab problem.

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    At the mid and upper elevations, skiers and riders could trigger recently developed wind slabs up to two feet deep in steep, wind-loaded starting zones.

Avalanche Discussion

Snow shower activity is anticipated to end overnight with little new snow accumulation. Skies will be mostly sunny on Monday. Temperatures will mostly in the single digits above and below zero. Valley temperatures may rise into the teens. Winds will back to the west, be light in the morning and increase to 15 to 20 with higher gusts in the afternoon.Conditions are prime for a serious avalanche accident in our forecast region. Persistent slab avalanches 2 to 4 feet in depth can be easily triggered at the mid and upper elevations by the weight of a single person. Dangerous slopes are steep and have a persistent weak layer of faceted snow at the base of the snowpack. These large slides are most likely to be triggered on northeast, east and north facing slopes, however they can occur on west through north to east aspects at the mid elevations and have occurred on most aspects at the higher elevations. In these areas the general avalanche hazard is expected to be considerable. The general avalanche hazard below an elevation of 7,500 feet and in areas above that elevation that were weak faceted snow does not exist at the base of the snowpack is low.

Régions couvertes